The present invention relates to a device for connecting a car door with a shaft door and for locking and unlocking the doors, a device for emergency unlocking of the car door and a method for emergency unlocking of a car door, wherein an entrainer, which is arranged at the car door, detachably connects, together with rollers arranged at the shaft door, the car door with the shaft door and a first locking mechanism locks and unlocks the car door and a second locking mechanism locks and unlocks the shaft door.
The car door is a component of an elevator car which is arranged to be movable along stopping points. The stopping points form access points for the elevator car and they are provided with shaft doors. The car door together with the shaft doors regulates access of elevator passengers or goods to the elevator car or to the stopping point. For this purpose, the car door is temporarily connected at the stopping point with the shaft door. Constrained locking means or locking mechanisms keep the car door and the shaft door locked when the car door is not disposed in the access region of the stopping point or is disposed in free travel and unlocks the car door and the shaft door when the elevator car is disposed in the access region of the stopping point and an access command is present.
A device is shown in the European Patent Specification EP 1 266 860 A1 by means of which a car door of an elevator car disposed in the region of a stopping point is opened in common with a shaft door. If the elevator car is located outside a stopping point, the car door remains locked by the same device. An entrainer parallelogram is closed for free travel and opens for coupling with the shaft door between two coupling rollers arranged at the shaft door. The encrainer parallelogram is guided by means of parallel levers and comprises a third rail which is actuated in the presence of the coupling rollers and thus unlocks the car door and in the absence of the coupling rollers, for example between the floors, leaves the car door in the locked position.
A disadvantage of the known device resides in the fact that the third rail with smallest dimensions has to be guided and mounted on a second rail. Moreover, a force element is required to keep the third rail in its operating position. This has the consequence that the device is sensitive to dirt and wear and thus maintenance-intensive. It needs many components and is thus cost-intensive.
A further disadvantage is a lack of emergency unlocking. This makes emergency evacuation of the elevator passengers difficult when the elevator car remains standing in the vicinity of a stopping point.